DENVER – Cooper Hjerpe’s flight to Denver on Saturday evening for his potential big-league debut was fairly smooth – a fitting final leg to a more turbulent journey to the Major Leagues that culminated with four perfect innings of relief for his first big league win in his first appearance.
“It was unbelievable,” Hjerpe said. “It was a great experience, great debut. Can't get much better than that. I felt really good from the get-go. Felt like everything was moving really well and pounding the zone.”
The Cardinals, who trailed 5-1 when Hjerpe entered in the fourth, took the series from Colorado with a 10-8 victory in the rubber match at Coors Field, pairing Hjerpe’s perfect six-strikeout performance with multi-hit games from Iván Herrera, Alec Burleson, Joshua Báez and Thomas Saggese and a go-ahead home run from Nolan Gorman in a six-run fifth inning.
“We're going to compete no matter the day, no matter where,” Herrera said after his fourth consecutive multi-hit game. “We're relentless out there.”
Hjerpe gives the Redbirds another tool for their stretch run, and Sunday’s outing proved to be well worth the wait.
“Everyone's journey is different,” Hjerpe, the Cardinals’ first-round Draft pick in 2022, said before making his debut. “Mine had a lot of bumps in the road, man. Sometimes those things are out of your control.
“I kind of came to terms, obviously, with this last surgery,” Hjerpe continued, noting the sizeable bump represented by 2025 Tommy John surgery. “It was the biggest [surgery] I've had so far. You have to accept it. You got to start from the ground up and kind of hit the ground running when you can and take it day by day.”
What Hjerpe did Sunday is eclipsed by only two Major League debuts with a longer perfect performance since at least 1900: Max Kranick, who went five innings on June 27, 2021, for the Pirates; and Max Scherzer, who went 4 1/3 innings on April 29, 2008, for the D-backs. Hjerpe got through four innings on 54 pitches, 41 for strikes.
Hjerpe, the Cardinals’ No. 18 prospect per MLB Pipeline, was called up from Triple-A Memphis on Sunday. He had arthroscopic elbow surgery in 2023 and ‘24, and he had been building back from his Tommy John surgery since being activated in the Minors on June 5.
“In my last outing, I threw [74 pitches], so we're in a pretty good spot now,” Hjerpe said. “A pretty hefty workload. I talked to [manager Oliver Marmol] today. I'll be ready in the bullpen for however many innings they need me.”
Marmol indicated he’d use Hjerpe’s preparation as a starter to complement the bullpen arms, bringing him in for clean innings as he did Sunday after Cade Winquest finished the third for starter Kyle Leahy.
“We will not use him as a reliever,” Marmol said. “He will piggyback, but he will stay on a starter's schedule.”
Marmol shared his excitement at the chance to see Hjerpe pitch before the game, and the outing exceeded his expectations.
“That was gross,” Marmol said. “Everything coming out of the hand was really good. Pounded the zone, over 75% strikes. Fastball was good. Landed the sweeper and the changeup at a super-high rate. Righties, lefties did not look comfortable. That was a lot of fun to watch. He went right after everybody, and good presence, kept his composure all the way through. That was impressive.”
Hjerpe took the spot of Hancel Rincon, who made his debut Friday and pitched again Saturday, generally struggling with seven runs in 1 1/3 innings. Rincon was optioned to Memphis.
Marmol said he likes what he has heard of Hjerpe’s potential, noting his “high ceiling. He’s got some funk. Swing and miss. Tough at-bat, left on left.”
Hjerpe posted a 0.95 ERA in August, pitching 19 innings and striking out 27. Over three Minor League seasons, he has posted a 3.26 ERA in 135 1/3 innings with 85 walks and 188 strikeouts.
Of his elevated game at the big league level, Hjerpe gave credit to his battery mate, Leo Bernal.
“It's just the confidence I had in Bernal,” Hjerpe said of what clicked for him. “He knows me very well, so that's definitely a confidence boost, being on the same page and not having to shake him off at all. Tip of the cap to him for sure.”
The 25-year-old from Davis, Calif., had been confident this debut was coming as he pitched in the Minors this season. He was given an inkling that it might be sooner rather than later a couple of days ahead of time.
“I slept with my ringer on that night,” Hjerpe recalled with a laugh. “I turned that thing all the way up. Yeah, I was definitely waking up if I got a call.”
Once he found out Saturday, it was a whirlwind trip to join the Cards in the second city of a three-city road trip.
“I was ecstatic to be on the way to Denver,” Hjerpe said.
Hjerpe took a little time to explore the ballpark before his first workout, checking out the wooded area behind the center-field fence next to the visitors’ bullpen.
“I didn't even know there was a trail back there in that forest area,” Hjerpe marveled. “That was a pretty sick experience. This place is awesome, and I’m happy to be around this group of guys.”
Hjerpe also had about 20 friends and family out in the stands, all of whom dropped what they were doing to get to Denver for his debut. He mentioned his wife, his parents, his best man and groomsmen from his wedding, and many more, and though they may have helped him feel comfortable as he took the mound, he left the hill with something extra.
“There's some confidence that your stuff plays to the next level,” Hjerpe conceded. “But at the same time, you don't want to get too big of a head – stay on the grindstone and work toward next week and help the team out.”